Study on Disaster Mechanism and Control Countermeasures of Adjacent Rock in Gob-Side Roadway of Inclined Coal Seam

Abstract

As the key engineering structure of continuous coal mining, the surrounding rock disaster mechanism of gob-side entry has always been a research hotspot. In purpose of researching the disaster mechanism of adjacent rock, this paper takes the background of the −240 working face of Dongbaowei 36^# coal seam as the backdrop, adopts the theoretical analysis, and calculates the dimension of the coal column, and the numerical simulation method analyzes the effect of the coal column on the deformation and damage characteristics of the adjacent rock and the stress environment, so as to put forward the control countermeasures of the adjacent rock and carry out the engineering validation. The results show that (1) based on the results of laboratory tests and field measurements, it is found that the destruction of the “roof–coal column” system is the main reason for the disaster of the adjacent rock. (2) Considering the influence of coal seam inclination, the preliminary determination of the dimension of the coal column ranges from 4.38 to 9.4 m; with this width increase, the deformation of the coal column is smaller, and the stress environment of the adjacent rock can be optimized. Considering the deformation characteristics of the adjacent rock, stress environment, and economic efficiency, it is more reasonable to determine the dimension of the coal column of 5 m. (3) The control countermeasures of coal pillar composite reinforcement technology and changing roof bolt cable parameters are put forward, and it is more reasonable to determine the bolt preload of the roof plate to be 75 kN and the pretightening force of the anchor cable to be 200 kN, and it is better for the roof plate anchor, anchor cable, and cooperative support effect; the on-site test found the maximum amount of the roof of the roadway to be 198 mm and the maximum amount of the two gangs to be 127 mm, which can meet the needs of the normal production. This study is aimed at providing theoretical and technical support for controlling the disaster of trapezoidal adjacent rock in inclined coal beds, as well as providing a reference for solving similar engineering problems.